Skip to content

X
xv6-public
提交 2ca11e63 创建 作者: David Benjamin's avatar David Benjamin
浏览文件
操作

Have descend return the radix level we stopped at

Rather awkward API, but it's enough to implement skipping of empty nodes.
上级 e10e8bda
隐藏空白字符变更
内嵌 并排
正在显示 包含 39 行增加 和 26 行删除
kernel/radix.cc
浏览文件 @ 2ca11e63
...@@ -5,8 +5,9 @@ ...@@ -5,8 +5,9 @@
#include "cpputil.hh" #include "cpputil.hh"
#include "radix.hh" #include "radix.hh"
// Returns the level we stopped at.
template<class CB> template<class CB>
void u32
descend(u64 key, markptr<void> *n, u32 level, CB cb, bool create) descend(u64 key, markptr<void> *n, u32 level, CB cb, bool create)
{ {
static_assert(key_bits == bits_per_level * radix_levels, static_assert(key_bits == bits_per_level * radix_levels,
...@@ -14,26 +15,29 @@ descend(u64 key, markptr<void> *n, u32 level, CB cb, bool create) ...@@ -14,26 +15,29 @@ descend(u64 key, markptr<void> *n, u32 level, CB cb, bool create)
assert(n); assert(n);
void *v = n->ptr(); void *v = n->ptr();
if (v == 0) { if (v == 0 && create) {
// Node isn't there. Just return.
if (!create)
return;
radix_node *new_rn = new radix_node(); radix_node *new_rn = new radix_node();
if (n->ptr().cmpxch_update(&v, (void*) new_rn)) if (n->ptr().cmpxch_update(&v, (void*) new_rn))
v = new_rn; v = new_rn;
else else
delete new_rn; delete new_rn;
} }
// Node isn't there. Just return.
if (v == 0) {
return level+1;
}
radix_node *rn = (radix_node*) v; radix_node *rn = (radix_node*) v;
u64 idx = key >> (bits_per_level * level); u64 idx = key >> (bits_per_level * level);
idx &= (1<<bits_per_level)-1; idx &= (1<<bits_per_level)-1;
markptr<void> *vptr = &rn->ptr[idx]; markptr<void> *vptr = &rn->ptr[idx];
if (level == 0) if (level == 0) {
cb(vptr); cb(vptr);
else return level;
descend(key, vptr, level-1, cb, create); } else {
return descend(key, vptr, level-1, cb, create);
}
} }
radix_elem* radix_elem*
...@@ -55,11 +59,14 @@ radix::search_lock(u64 start, u64 size) ...@@ -55,11 +59,14 @@ radix::search_lock(u64 start, u64 size)
radix_range::radix_range(radix *r, u64 start, u64 size) radix_range::radix_range(radix *r, u64 start, u64 size)
: r_(r), start_(start), size_(size) : r_(r), start_(start), size_(size)
{ {
for (u64 k = start_; k != start_ + size_; k++) for (u64 k = start_; k != start_ + size_; k++) {
descend(k, &r_->root_, radix_levels-1, [](markptr<void> *v) { if (descend(k, &r_->root_, radix_levels-1, [](markptr<void> *v) {
while (!v->mark().xchg(true)) while (!v->mark().xchg(true))
; // spin ; // spin
}, true); }, true) != 0) {
panic("radix_range");
}
}
} }
radix_range::~radix_range() radix_range::~radix_range()
...@@ -67,10 +74,13 @@ radix_range::~radix_range() ...@@ -67,10 +74,13 @@ radix_range::~radix_range()
if (!r_) if (!r_)
return; return;
for (u64 k = start_; k != start_ + size_; k++) for (u64 k = start_; k != start_ + size_; k++) {
descend(k, &r_->root_, radix_levels-1, [](markptr<void> *v) { if (descend(k, &r_->root_, radix_levels-1, [](markptr<void> *v) {
v->mark() = false; v->mark() = false;
}, true); }, true) != 0) {
panic("~radix_range");
}
}
} }
void void
...@@ -82,15 +92,18 @@ radix_range::replace(u64 start, u64 size, radix_elem *val) ...@@ -82,15 +92,18 @@ radix_range::replace(u64 start, u64 size, radix_elem *val)
assert(start >= start_); assert(start >= start_);
assert(start + size <= start_ + size_); assert(start + size <= start_ + size_);
for (u64 k = start; k != start + size; k++) for (u64 k = start; k != start + size; k++) {
descend(k, &r_->root_, radix_levels-1, [val](markptr<void> *v) { if (descend(k, &r_->root_, radix_levels-1, [val](markptr<void> *v) {
void* cur = v->ptr().load(); void* cur = v->ptr().load();
while (!v->ptr().cmpxch_update(&cur, val)) while (!v->ptr().cmpxch_update(&cur, val))
; // spin ; // spin
val->incref(); val->incref();
if (cur) if (cur)
((radix_elem*) cur)->decref(); ((radix_elem*) cur)->decref();
}, true); }, true)) {
panic("radix_range::replace");
}
}
} }
radix_elem* radix_elem*
......
您添加了 0 人 到此讨论。请谨慎行事。
请先完成此评论的编辑！
请 注册 或者 后发表评论